The IPCC’s sixth assessment on how climate change impacts the world

The threat that climate change poses to human well-being and the health of the planet is “unequivocal”, says the latest report from the United Nations’ Intergovernmental Panel on Climate Change (IPCC).

The expansive review – which forms the second part of the IPCC’s sixth assessment report (AR6) – warns that any further delay in global action to slow climate change and adapt to its impacts “will miss a brief and rapidly closing window of opportunity to secure a liveable and sustainable future for all”.

The report follows the publication of the first part of AR6, released in August last year, which set out how and why the Earth’s climate is changing.

Over the past two weeks, government delegations have been meeting during a two-week online approval session to agree on the high-level “summary for policymakers” section.

The final report is published against the backdrop of Russia’s invasion of Ukraine, which forced some members of the Ukrainian delegation to pull out of the approval session and hide in bomb shelters. One member commented that “we will not surrender in Ukraine and we hope the world will not surrender in building a climate resilient future”.

Focusing on the impacts of global warming and efforts to adapt to it, the report lays bare how climate change is being felt across the planet. Among the findings, the report concludes that:

  • Climate change has already caused “substantial damages and increasingly irreversible losses, in terrestrial, freshwater and coastal and open ocean marine ecosystems”.
  • It is likely that the proportion of all terrestrial and freshwater species “at very high risk of extinction will reach 9% (maximum 14%) at 1.5C”. This rises to 10% (18%) at 2C and 12% (29%) at 3C.
  • Approximately 3.3 to 3.6 billion people “live in contexts that are highly vulnerable to climate change”.
  • Where climate change impacts intersect with areas of high vulnerability, it is “contributing to humanitarian crises” and “increasingly driving displacement in all regions, with small island states disproportionately affected”.
  • Increasing weather and climate extreme events “have exposed millions of people to acute food insecurity and reduced water security”, with the most significant impacts seen in parts of Africa, Asia, Central and South America, small islands and the Arctic.
  • Approximately 50-75% of the global population could be exposed to periods of “life-threatening climatic conditions” due to extreme heat and humidity by 2100.
  • Climate change “will increasingly put pressure on food production and access, especially in vulnerable regions, undermining food security and nutrition”.
  • Climate change and extreme weather events “will significantly increase ill health and premature deaths from the near- to long-term”.

The report warns that if global warming passes 1.5C – even if overshooting that global average temperature temporarily before falling back again – “human and natural systems will face additional severe risks”, including some that are “irreversible”.

In response to these impacts, adaptation efforts “have been observed across all sectors and regions, generating multiple benefits”, the authors say, but this progress is “unevenly distributed” as well as being “fragmented, small in scale [and] incremental”.

As a result, “gaps exist between current levels of adaptation and levels needed to respond to impacts and reduce climate risks”, the report warns.

These gaps are “partially driven by widening disparities between the estimated costs of adaptation and documented finance allocated to adaptation”, the authors say, adding that the “overwhelming majority” of global climate finance has so far been targeted at climate change mitigation.

Commenting on the report, UN secretary-general António Guterres described it as “an atlas of human suffering and a damning indictment of failed climate leadership”.

Calling on all G20 governments to “dismantle their coal fleets”, Guterres warned that “as current events make all too clear, our continued reliance on fossil fuels makes the global economy and energy security vulnerable to geopolitical shocks and crises”.

In the in-depth Q&A below, Carbon Brief unpacks the key findings of the report and the developments since the IPCC’s last assessment. Please use the links to navigate between the sections.

  1. What is this report?
  2. How is climate change affecting land ecosystems?
  3. What impact is global warming having on marine life?
  4. How is climate change affecting the world’s water?
  5. What does the report say about impacts on food and agriculture?
  6. What risks does climate change pose to the world’s cities?
  7. What does the report say about public health, conflict and migration?
  8. How does climate change affect poverty and progress towards the sustainable development goals?
  9. How is the world adapting to climate change?
  10. Are there limits to what adaptation can achieve?
  11. What does the report say about ‘loss and damage’?
  12. What are the risks of ‘maladaptation’ and the unintended consequences of tackling climate change?
  13. What role can nature-based solutions play in adaptation and mitigation?
  14. What does the report say about climate-resilient development?
  15. What information about specific regions does the report contain?

This is an edited version taken from the Carbon Brief website.